Technique for ultra-high vacuum electron microscopy on the epitaxial growth processes of thin films and on microtopography of surfaces and the results of the observations were surveyed. The currently accepted concepts of the growth mechanisms, which were based on poor observations for a very limited number of epitaxial systems, were critisized on the basis of in-situ observations in clean condition for many varieties of systems. A number of microtopographic aspects and behaviours of monotomic layer levels on clean surfaces and on the surfaces with deposits of silver, gold and silicon were revealed by the transmission and reflection electron microscopies.